石家庄地区近70年来伴随经济发展的水文环境变化分析

论文系统分析了石家庄地区70年来伴随社会经济发展的水资源开发历史,结合水文资料探讨了人类活动对区域水文环境变迁的影响。并通过对地下水采样,结合室内水化学和氚同位素测定,确认区域地下水补给来源主要是通过河道得到线状的垂向补给,和上游含水层的侧向补给两种天然途径。城市及工农业发展改变了区域水循环系统的补排结构。河流断流减少了地下水的垂向补给,造成地下水的补给源从原来的天然垂向补给和上游的侧向补给,变为单一的侧向补给。另一方面,大量开采地下水已成为区域地下水排泄的主要方式。其中用于农业灌溉的大部分以蒸发、蒸腾的形式耗散于大气,无法回补。地下水位的持续下降、地下水化学类型转变及其空间分布显示了水量和水质以及生态环境的变化。     

黄河中游城镇化与生态系统服务耦合关系的时空变化

城镇化是影响区域生态安全格局的重要因素,厘清城镇化与生态系统服务之间的关系,可为促进黄河流域生态保护与高质量发展提供决策参考。在分析2000—2018年黄河中游城镇化与生态系统服务时空格局的基础上,采用耦合协调度模型剖析了二者耦合关系的时空变化特征。研究发现：2000—2018年间,黄河中游地区综合城镇化水平提高72.24%,空间分布总体呈“南高北低”、以经济发达县区或城市群为中心向外递减的趋势;粮食生产、水源涵养、土壤保持和固碳服务量均呈增加趋势,且呈不同的空间分布态势;粮食生产、水源涵养、土壤保持和固碳服务与综合城镇化水平的耦合协调度总体呈上升趋势,但汾渭平原的耦合协调度普遍较低,而经济发达县区的耦合协调度普遍较高。     

Dynamic changes in microbial activity and community structure during biodegradation of petroleum compounds： A laboratory experiment

With 110-d incubation experiment in laboratory,the responses of microbial quantity,soil enzymatic activity,and bacterial community structure to different amounts of diesel fuel amendments were studied to reveal whether certain biological and biochemical characteristics could serve as reliable indicators of petroleum hydrocarbon contamination in meadow-brown soil,and use these indicators to evaluate the actual ecological impacts of 50-year petroleum-refining wastewater irrigation on soil function in Sbenfu irrigation area.Results showed that amendments of≤1000 mg/kg diesel fuel stimulated the growth of aerobic beterotrophic bacteria,and increased the activity of soil dehydrogenase,hydrogenperoxidase,polypbenol oxidase and substrate-induced respiration.Soil bacterial diversity decreased slightly during the first 15 d of incubation and recovered to the control level on day 30.The significant decrease of the colony forming units of soil actinomyces and filamentous fungi can be taken as the sensitive biological indicators of petroleum contamination when soil was amended with≥5000 mg/kg diesel fuel.The sharp decrease in urease activity was recommended as the most sensitive biochemical indicator of heavy diesel fuel contamination.The shifts in community structure to a community documented by Sphingomonadaceae withinα-subgroup of Proteobacteria could be served as a sensitive and precise indicator of diesel fuel contamination.Based on the results described in this paper,the soil function in Shenfu irrigation area was disturbed to some extent.     

河北省38°N生态样带生态系统服务功能时空变化

河北省38°N生态样带是一条由太行山区-山前平原区-低平原区-滨海平原区组成的典型生态样带。论文引进区域修正系数和环境成本系数对前人的生态系统服务功能价值评估模型进行改进,并对该生态样带土地利用变化驱动下的生态系统服务功能时空变化进行了研究。结果表明:1990-2008年,该生态样带的生态系统服务功能价值总量由334.83×10⁸元增至360.13×10⁸元,但食物生产功能价值持续减少,累计减少了4.67%。太行山区的生态系统服务功能单位面积价值为西高东低,主要由林地和草地提供;山前平原区和低平原区的生态系统服务功能单位面积价值较低且分布均匀,主要由农田提供;滨海平原区的生态系统服务功能单位面积价值东部明显高于中西部,主要由水体和湿地提供。     

花江小流域石漠化过程中的土壤有机碳氮的变化

以花江峡谷区1.2 km2小流域为研究对象,通过设置不同喀斯特石漠化强度的样地,研究不同等级石漠化样地的土壤有机碳、全氮含量在石漠化过程中的变化。结果表明,喀斯特生境中土壤具有高度异质性,人为干扰方式对土壤有机碳、全氮含量变异性的影响很大;樵采石漠化样地小生境土壤有机碳、全氮含量维持在较高水平,开垦石漠化样地小生境土壤有机碳、全氮含量较低;随着石漠化程度的加剧,樵采和开垦系列样地土壤有机碳、全氮含量呈现不断降低的趋势,这在一定程度上体现了石漠化过程的土壤退化本质。小流域内石漠化成因类型的划分对揭示石漠化过程中的土壤退化是必须的。     

汉江上游不同林龄麻栎林枯落物的水文功能评价

麻栎林普遍存在于汉江上游,其涵养水源能力的发挥对维持汉江上游流域生态平衡具有重要的作用。于2020年12月对汉江上游天柱山3个不同林龄(15a、25a、33a)的麻栎林样地进行了枯落物厚度和蓄积量调查,利用浸泡法测定了枯落物各水文功能指标,运用熵权法对3个林龄麻栎林枯落物的水源涵养能力进行了综合评价。结果表明：麻栎林枯落物总厚度在3.0—4.8 cm,蓄积量介于13.76—14.39 t·hm^-2,二者在林龄之间差异不显著(P=0.591;P=0.993);不同林龄麻栎林内半分解层枯落物的瞬时持水量和吸水速率略大于未分解层的;二者的枯落物瞬时持水量均在10min内快速增加,20min后缓慢增加,其与浸泡时间呈对数关系,R²为0.764 6—0.960 6;未分解层枯落物的瞬时持水量表现为15 a>33 a>25 a,而半分解层的则表现6 h之前25 a的略大于15 a的,之后二者的持水量几乎相等,但二者均大于33 a的;相应的不同林龄内未分解层和半分解的枯落物吸水速率均在20 min内很快降低,2 h之后吸水速率以接近0的趋势变小...     

Assessing the effects of land use changes on soil sensitivity to erosion in a highland ecosystem of semi-arid Turkey

There has been increasing concern in highlands of semiarid Turkey that conversion of these systems results in excessive soil erosion, ecosystem degradation, and loss of sustainable resources. An increasing rate of land use/cover changes especially in semiarid mountainous areas has resulted in important effects on physical and ecological processes, causing many regions to undergo accelerated environmental degradation in terms of soil erosion, mass movement and reservoir sedimentation. This paper, therefore, explores the impact of land use changes on land degradation in a linkage to the soil erodibility, RUSLE-K, in Cankiri–Indagi Mountain Pass, Turkey. The characterization of soil erodibility in this ecosystem is important from the standpoint of conserving fragile ecosystems and planning management practices. Five adjacent land uses (cropland, grassland, woodland, plantation, and recreational land) were selected for this research. Analysis of variance showed that soil properties and RUSLE-K statistically changed with land use changes and soils of the recreational land and cropland were more sensitive to water erosion than those of the woodland, grassland, and plantation. This was mainly due to the significant decreases in soil organic matter (SOM) and hydraulic conductivity (HC) in those lands. Additionally, soil samples randomly collected from the depths of 0–10 cm (D ₁) and 10–20 cm (D ₂) with irregular intervals in an area of 1,200 by 4,200 m sufficiently characterized not only the spatial distribution of soil organic matter (SOM), hydraulic conductivity (HC), clay (C), silt (Si), sand (S) and silt plus very fine sand (Si + VFS) but also the spatial distribution of RUSLE-K as an algebraically estimate of these parameters together with field assessment of soil structure to assess the dynamic relationships between soil properties and land use types. In this study, in order to perform the spatial analyses, the mean sampling intervals were 43, 50, 64, 78, 85 m for woodland, plantation, grassland, recreation, and cropland with the sample numbers of 56, 79, 72, 13, and 69, respectively, resulting in an average interval of 64 m for whole study area. Although nugget effect and nugget effect–sill ratio gave an idea about the sampling design adequacy, the better results are undoubtedly likely by both equi-probable spatial sampling and random sampling representative of all land uses.     

Interconversions and toxicity changes in hexachlorocyclohexane isomers on dispersion in water

Abstract

Studies on the transformations of hexachlorocyclohexane isomers, α‐, β‐, γ‐ and δ‐, in aqueous solution were carried out at 25 ± 1°C over a period of four weeks. Gas liquid chromatographic technique was used for analysis. The results indicated a loss as well as interconversion of all the four isomers with time. The resulting changes in toxicity of the aqueous solution were studied against Drosophila using topical application. Toxicity studies with aqueous solution of technical hexachlorocyclohexane were simultaneously carried out for comparison. Toxicity of the aqueous solutions of α‐, β‐, and δ ‐isomers showed an increase while that of the γ‐isomer decreased significantly during the four week experimental period. Aqueous solution of technical HCH was equally toxic as that of the γ‐isomer initially and did not show much decrease in its toxicity at the end. Changes in toxicity of the individual isomer solutions were considered to be due, in part, to interconversions of HCH isomers.     

四川省森林资源动态变化及其影响因素分析

四川省森林资源在长江上游生态屏障建设和长江经济带发展中具有举足轻重的地位,其动态变化特征及其影响因素对区域生态文明建设乃至全国生态安全格局具有重要的理论和现实意义.针对四川省近20 a森林资源动态变化,选取森林面积、人均森林面积、森林蓄积量、活立木蓄积量、人工造林面积5个森林资源指标,GDP、人均GDP、年末常住人口、...     

中老缅泰交界地区土地利用变化信息挖掘与国别对比

基于Landsat TM/ETM数据,从土地利用空间分布特征、时空变化规律、土地利用程度三个方面,对中老缅泰交界地区1990-2010年土地利用变化特征进行分析。研究表明：① 橡胶园、茶园为增幅最大的土地利用类型,轮歇农地、建设用地、长期性农地也有一定幅度的增加,有林地、灌木林、草地、水域有所减少。② 有林地、灌木林之间的转移及其与长期农地、轮歇农地、橡胶园之间的转移,决定着中老缅泰交界地区土地利用变化特征。中老缅泰交界地区土地利用变化本质上受到市场经济、国家政策、人口迁移、基础设施建设等因素的影响。③ 橡胶园和茶园的时空变化基本表现为面积净值增加,空间位置交换变化非常小。长期农地面积变化不大,但存在较大幅度的空间位置转变;水域、轮歇农地变化以空间位置交换为主。草地、灌木林、有林地、建设用地交换变化和净变化比例相当。④ 1990-2010年,中老缅泰交界地区土地利用程度有所增加,其中,泰国境内土地利用程度最高,老挝和缅甸境内的土地利用程度最低。2000年后中老缅泰交界地区土地利用程度增幅明显加大。其中,中国和缅甸境内土地利用程度后期增幅减小,泰国境内土地利用程度后期增幅变大,老挝境内土地利用程度实现了由前期减少到后期增加的转变。